James Smith
London — One of the youngest children in the world to receive a new type of gene therapy to treat genetic deafness can now hear for the first time in his life. The family of a child taking part in a medical trial has called the change in their daughter “mind-blowing”.
Opal Sandy, now 18 months old, was born completely deaf due to a defect in the OTOF gene, which produces a protein called Otoferlin. Otoferlin allows communication between cells in the inner ear, or cochlea, and the brain.
As part of a trial carried out by the University of Cambridge, Opal received an infusion of a working copy of the OTOF gene into her right ear. The surgical procedure lasted just 16 minutes and was carried out shortly before her first birthday.
Within a few weeks, Opal could hear loud sounds.
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In an interview with partner network CBS News BBC NewsOpal’s mother, Jo Sandy, described seeing her daughter respond to the sound for the first time as “absolutely mind-blowing”.
She immediately texted her partner, James Sandy, who was at work.
“I’m not sure I believed it at first,” he told the BBC. “I think she said it was just a fluke, you know? She must have reacted to something else.”
He immediately returned home and removed his daughter’s cochlear implant, a device that bypasses damaged auditory cells by directly stimulating the auditory nerves in the inner ear, and began testing her response to loud knocks at the bottom of the stairs. She answered.
Twenty-four weeks after surgery, Opal was able to hear whispers – prompting doctors to describe the level of hearing in her right ear as “near normal.”
Opal’s doctors “played the sounds Opal was turning to and we were amazed at how soft and quiet it was,” her father said. “I think they were sounds that, in everyday life, you might not notice.”
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The girl even started talking, the family told the BBC, saying words like “mummy” and “daddy”.
Opal tolerated the procedure and the gene therapy itself well, and suffered no adverse effects after the treatments, according to Regeneron, the US company behind the therapy being tested in the Chord study. The study involves children at sites in the US, Britain and Spain.
In the first of three parts of the trial, a low dose of gene therapy is administered to three children who are deaf in only one ear. This group includes Opal. A higher dose is also given to another group of three children, also in one ear. If it is safe, more children will receive infusions, in both ears, in a next phase.
The Children’s Hospital of Philadelphia announced in January that an 11-year-old Spanish boy, who was also born unable to hear, has seen improvements in his hearing after becoming the first person to receive gene therapy for congenital deafness in the US
Congenital deafness – defined as hearing loss present at birth – is believed to affect about 1.7 out of every 1,000 children born in the U.S.
Although devices such as hearing aids and cochlear implants help people with different types of hearing loss by enhancing sound, they do not restore the full spectrum of sound.
Opal’s experience and other data from the Chord study were presented at the annual conference of the American Society for Gene and Cell Therapy, taking place this week in Baltimore.
